This invention relates to magnetic head assemblies and, more particularly, to magnetic head assemblies having a read/write transducer and a pair of erase transducers.
Magnetic head assemblies have long been used for reading and writing data on magnetic recording surfaces, such as those which appear on magnetic recording disks, both rigid and flexible. In flexible disk drives, the magnetic head assembly normally contacts or is in close proximity to the recording surface during reading and writing. In the case of contacting magnetic head assemblies, a compliance member is provided in the disk drive for assuring continuous contact during rotation of the recording disk about its axis.
In order to define guard bands between adjacent data tracks written by the magnetic head assemblies used in flexible disk drives, and to reduce noise in such guard bands when the data is read back, a pair of erase transducers are positioned on either side of the read/write transducer. The erase transducers are normally also positioned rearwardly of the read/write transducer relative to the path of movement of the magnetic recording surface during rotation thereof in the disk drive. Such pair of erase transducers are oftentimes referred to as "tunnel erase" transducers, as they serve to erase the edges of each data track just after it has been written by the read/write transducer.
In present flexible disk drives, the magnetic head assembly is normally positioned with the lengthwise extent of its read/write gap lying along a line which is parallel to a radial line from the axis of rotation of the disk and which intersects such axis. Additionally, the erase gaps generally lie along a line parallel to such radial line, since they are formed on the head assembly parallel lengthwise to the read/write gap. In view of this relationship, it was found that, during erasure of the edges of a just written data track, a portion of the data track itself would be erased by one erase transducer, while the other erase transducer would not completely erase previous data and noise adjacent to the other side of the track, thereby leaving remnant data and noise adjacent such other side. These adverse effects are caused by the curvature of the track, and become more pronounced as the radius of the track decreases.
At least one manufacturer of flexible disk drives has attempted to overcome this problem by mounting the head assembly in the drive such that it is rotated by an amount sufficient to compensate for the curvature of the tracks. While this approach may reduce the adverse track curvature effects above described, it necessarily introduces undesirable azimuth errors, since the lengthwise extent of the read/write gap would no longer be along a line intersecting the axis of rotation of the disk.
It would be desirable, therefore, to provide a magnetic head assembly having a read/write transducer and a pair of erase transducers wherein the adverse track curvature effects as above described are substantially reduced, if not eliminated, while not thereby introducing azimuth or other errors.